Muffler



May 16, 1933.

A. Y; DODGE MUFFLER Filed May si 2 sheets-sheet 1 JNVENTUR.

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A. Y. DODGE May 16, l1933.

2 Sheets-Sheet 2 Filed May 5l, 1930 INVENTOR. Y Orgfe/f L] Il-l..

Patented May 16, 1933 PATENT OFFICE UNITED STATES ADI'EL Y. DODGE, OF SOUTH BEND INDLANA, SSIGNOR TO BENDIX AVIATION CORPORA- TION, OF SOUTH BEND,7 INDIANA, .A CORPORATION F DELAWARE IUFFLER `Application filed Hay 3l,

,f5 4a muiiier for an internal combustion engine adapted to deaden the sound incident to discharge of the burnt gases and to eliminate back pressure in the cylinders of the engine. Another object of theinvention is to pro l m vide means, whereby some portion of the exhaust'gases of an internal combustion engine may be ejected through a passage direct to the atmosphere.

Another object of the invention is to provide a muilier inv which a portion of the exhaust gases of an internal comhustion env e may be discharged into the atmosphere directly from the disch-arge end of the exhaust pipe and the remainder expanded so that the sound waves may he reiiected in various directions to cause interference and thus dissipation.

Another object of the invention is to provide a muiiier for an internal combustion engine in which the velocity of the sound waves and the exhaust gases is momentarily interrupted and must be accelerated again before discharging into the atmosphere.

A urther object of the invention is to provide a muilier for'an internal combustion engine in which a portion Ao the exhaust gases may be discharged into the atmosphere direct from the discharge end of the exhaustl p ipe and the remain er expanded and reflected to dissipate the sound waves.

A further object of the invention is to provide a comparatively light muiiier casing having great strength and rigidity.

40 A further object of the invention is'to provide a muiiler having a casingvadapted to refiectv sound waves in Vvarious directions to cause interference and hence dissipation of the sound waves. f V

Yet a further object of the invention is to provide a muiiier for an internal combustion engine having means for' causing an interruption of the travel of the sound waves and gases and means associated therewith for reecting the sound waves in various di- 1i930. Serial No. 458,718.

rections to cause interference and hence dissipation thereof.

A s 'll :further object oi' the inventionv is to provide a muer having a casing provided with a corrugated wall adapted to r es' dect sound waves in various directions to cause interference and dissipation oi" the sound waves.

Other objects of the invention will appear from the following description taken in conce nection with the drawings, which form a part oi this specification, and in which:

Figure l is a sectional view of a mndier embodying the invention;

Figure 2 is a sectional view or a modiiicaas tion illustrating an exhaust pipe having an enlarged cross section centrally disposed within the nimmer casing;

Figure 3 is a sectional view of another modication illustrating a mumer casing 7e embodying the invention and a divided exhast pipe on which the casing is positioned; nn

Figures d and 5 are sectional views of modifications in the exhaust pipe.

Figure 6 is an elevation and Figure '8' is a sectional view of a further modification or the invention. Referring to the drawings for more specific details of the invention, 10 represents an so exhaust pipe having a plurality of apertures 11 arranged therein in spaced relation and positioned on the exhaust pipe is a casing l2. This casingfencloses the perforated portion of theexhaust p ipe.

As shown, the casing is provided with corresponding end portions 13 provided with flanges 14 which fit snugly on the pipe l0 and connecting the end portions 13 is a corrugated Wall 15.' This corrugated wall 90 materially increases the strength and rigidity with but slight increase ,in the weight of the casing.

n this type of muiier, practically alll of the hack pressure created in the cylinders of an'engine is eliminated because a portion of the exhaust gases of the engine is discharged into the atmosphere directly from the discharge end of the exhaust pipe and the remainder 1s expand d through the aperf` f1 1 0 `modification of tures 11 and reflected together with the sound wavesincident thereto by the corrugated wall 15 in various directions inside ofv the muler, causing an interference between the sound waves, resulting in dissipation thereof.

In Figure 2, I have shown a modified form of the invention wherein the perforated portion of the exhaust pipe is enlarged, as shown at 16. This enlargement will cause an interruption in the travel ofthe sound waves and the gases. Due to the large cross sectional area of the exhaust pipe, the velocity of the gases and sound waves will be reduced momentarily and must again be accelerated in order to pass through the pipe and as the ases are expanded through the perforatlons 11, the sound waves accompanying the gases will be reflected by the corrugated wall 15 to cause interference and dissipation thereof.

In Figure 3 I have illustrated another the invention wherein the exhaust pipe 10 is divided within the casing 12, so that the gases may be freely ex anded within the casingand reflected by t e corrugated wall to cause interference and dissipation ofthe sound waves. In this embodiment, the adjacent ends of the exhaust pipe are perforated as at 11 and the end portions are spread or rolled to stren hen the respective ends of the pipe and len rigidity thereto.

In Figures 4 and 5, I have shown further modifications wherein the exhaust pipe is offset as indicated at 17, so that the perforated portion is inclined within the casing and the exhaust end extends through one of the ends 13 of the casing near the rim thereof, the casing being provided with a drain duct or opening 18 to permit the passage of products due to condensation in the casing.

. derstood they t is to be observed that in Figure 5 the exhaust pipe extends dia onally within the casin from one end to t e other.

In res 6 and 7 I have shown a further mfiilication of the invention. In this embodiment the casing is corru or iiuted longitudinally or arallel to its axis.

The lresult is ract'ical y the same in each of the modifications shown, that is, the discharging of a portion of the exhaustgases of the engine directly into the atmosphere in other specific mechanical structures, I do not intend to be limited to those shown, except as such limitations are clearly imposed by the appended claims.

Having thus described the various lfeatures of the invention, what I claim as new and desire to secure by Letters Patent is:

1. A muler for exhaust gases comprising an exhaust pipe having an enlarged perforated portion oval in longitudinal section and a casing enclosing the enlarged perforated portion having a corrugated wall.

2. A muler for exhaust gases comprising an unobstructed cylindrical exhaust pipe having its diameter enlarged at one portion to form a chamber for decreasing the velocity of the gases passing through the exhaust pipe, the walls of said chamber being perforated and a corrugatedcasing enclosing the chamber.

3. A mumer for exhaust gases comprising an unobstructed pipe having its diameter enlarged Aat yone portion to form a chamber for decreasin the velocity of the gases passing through t e pipe, the walls of said chamber being ,provided throughout their area with perforations, and a transversely corrugated casing enclosing the chamber.

4. A muiller for exhaust gases comprisin a corrugated casing, two alined unobstructe pipe sections forming inlet and outlet conduits for the casing and an enlarged section forming an expansion chamber between the pipe sections havingeperforations maintaining communication tween the chamber and the interior of the casing, the corrugations of the casing surrounding said enlarged section.

In testimony whereof, I have hereunto si ed m name.

gn y ADIEL Y. DODGE.

from the discharge end of the exhaust pipe with an interruption in the travel of t sound waves and gases and the reflection thereof in various directions inside of the mumer casing, so that an interference will be set up which will cause the sound to dissipate itself. f

While preferred embodiments of the invention have been described, it is to be unare given merely as examples of the underlyin principles of the invention and since tese may be incorporated llc 

